JAKARTA (AP) — The giant U.S.-owned gold and copper mine in eastern Indonesia where 28 workers died in a collapse said Tuesday it has government approval to resume milling and underground mine operations.

Indonesia’s government ordered the shutdown of the massive Grasberg mine in easternmost Papua province during the investigation of the May 14 collapse of its Big Gossan underground training facility. Last month, it approved the resumption of some activities, including open pit mining.

Mine operator PT Freeport Indonesia said in a statement Tuesday that it received approval from the Ministry of Energy and Mineral Resources to restart milling and underground mining. It did not say when the underground operation will be restarted, but pledged to take all corrective actions needed to ensure high safety standards.

“Throughout our long history of operations in Indonesia, the safety of our workers remains our number one priority and commitment,” said Rozik Soetjipto, president director of PT Freeport Indonesia. “We are committed to take all actions required for our worker safety.”

After the collapse, Indonesian President Susilo Bambang Yudhoyono ordered officials to thoroughly evaluate all mining companies in the country to ensure mining safety.

The Grasberg mine, owned by Phoenix, Arizona-based Freeport-McMoRan Copper & Gold Inc., produces around 220,000 tons of ore per day — 140,000 tons from its open mine and 80,000 from an underground mine.

More than 20,000 workers are employed at the mine, which has repeatedly been targeted by arson, roadside bombs and blockades since production began in the 1970s. It is located in the remote mountains of resource-rich but impoverished Papua, which is home to a decades-long, low-level separatist insurgency.